I have a 9 year old boy starting fourth grade at Riverside Christian School located in California. Most teachers agree that there isn't enough parental involvement in their children's education these days. I among others, don't subscribe to that ideology. Here is what I do. I meet with teachers of the next grade level higher and take note of what they are currently teaching. This allows me to prepare my son during the summer break for what he will encounter in his upcoming class. However, during the school year I teach my son algebra. My son has ADHD and thus preparation is especially important.
As for teachers, we need not quench their enthusiasm and passion. Its pretty disheartening when a prospective teacher is taught creative teaching methods in college only find out that on the job he or she must abide by an established teaching format. I favor the teacher in Oregon that teaches calculus by having the students build a kayak. Students accomplish much more with a passionate teacher than with a boring one. This is why politicians don't make good mentors.